Circuit breaker with positive relatch



Dec. 23, 1969 G. s. HARPER I 3, 1

CIRCUIT BREAKER WIfIHPOSITIVE RELA'TCH Filed Nov. 13, 1967 6 Sheets-Sheet l STEVENS, DAV/5', M/LLEI? 8 MOSHE/P ATTORNEY Dec. 23, 1969 G. s. HARPER 3,486,140

CIRCUIT BREAKER WITH POSITIVE RELATCH Filed Nov. 13, 1967 6 Sheets-Sheet 2 GEORGE 5. HARPER //Vl E/V7'0/? STEVENS DAV/.5 M/LLE/P 8 MOSHE/P ATTORNEY Dec. 23, 1969 G. s. HARPER I 3,486,140

CIRCUIT BREAKER WITH POSITIVE RELATCH Filed Nov. 13, 1967 6 Sheets-Sheet 5 GEORGE S. I HA RPER IN VE/V 7'01? STEVENS DAV/S, MILLER 8 MOSHE/P ATTORNEY Dec. 23, 1969 G. SIHARPER 3,486,140

CIRCUIT BREAKER WITH POSITIVE RELA'ICH Filed Nov. 13, 1967 6 Sheets-Sheet 4 F/ g 50 H 5b GEORGE 5 HARPER INVENTO/P STEVENS DAV/5 MILLER 8 MOSHE? ATTORNEY Dec. 23, 1969 c. s. HARPER CIRCUIT BREAKER WITH POSITIVE RELATCH 6 Sheets-Sheet 5 Filed Nov. l l96'7 F/g. 80 F/g. 85

O F/g. 90

F/g. 9b

GEORGE E. HARPER I/VVE/VTOR $7'EVEN$,DAV/$ MILLER 8 MOSHER A 7' TOR/VE Y Dec. 23, 1969 G. s. HARPER 3,486,140

CIRCUIT BREAKER WITH POSITIVE RELATCH Filed Nov. 13, 1967 6 Sheets-Sheet 6 GEORGE 5 HARPER //V I/E/V TOR STEVENS DAV/.5 MILLER 8 MOSHER A 7'7'0R/VEY United States Patent 3,486,140 CIRCUIT BREAKER WITH POSITIVE RELATCH George S. Harper, Cambridge, Md., assignor to Airpax Electronics Incorporated, Cambridge, Md., a corporation of Maryland Filed Nov. 13, 1967, Ser. No. 682,081 Int. Cl. H01h 9/20, 75/00, 73/02 US. Cl. 335-168 6 Claims ABSTRACT OF THE DISCLOSURE A circuit breaker having both means to adjust the tension of the armature spring and positive relatching. The armature spring tension is controlled by the selective rotation of an element bearing one end of the spring, the other end engaging the armature. -Relatching is accomplished through a contact bar and link by the contact bar spring to positively relatch the mechanism after each electrical tripping of the unit.

The present invention is related to and constitutes an improvement of the circuit breaker described in both my Patent 3,251,232, titled, Toggle Mechanism for Circuit Breakers, and issued May 17, 1966, and my copending application 545,434 titled, Circuit Breaker, and filed Apr. 26, 1966, now Patent 3,412,351.

One of the features of the present invention is the means of adjusting the tension on the armature spring. This is accomplished by a self locking hexagonal washer which, While holding the fixed end of the armature spring, can be rotated to obtain the correct spring pressure on the armature and then released to a self locking position.

Another feature of this invention is a positive means of relatching the mechanism, through the contact bar and link, by the contact bar spring so that the mechanism is positively relatched each time the unit is tripped electrically.

Another object of this invention is to provide an internal trip bar and the hexagonal handle pin whereby a multipole unit can be built with one handle per pole per unit or just one handle per multipole unit, whichever arrangement is desired.

A further object of the present invention is to provide an improved circuit breaker mechanism which can be readily and economically produced.

The means for accomplishing the foregoing objects and other advantages, which will be apparent to those skilled in the art, are set forth in the following specification and claims, and are illustrated in the accompanying drawings dealing with a basic embodiment of the present invention. Reference is made now to the drawings in which:

FIG. 1 is a side view of the circuit breaker, with half the case removed, showing the operating mechanism in the On position with the contacts closed;

FIG. 2 is a view similar to FIG. 1 showing the mechanism immediately after it has been tripped electrically so the contacts are open, the cam and holder are disengaged but the operating handle has not started to rotate to the Off position;

FIG. 3 is a view similar to FIGS. 1 and 2 showing the contacts open, the handle in the Off position and the cam, sear pin and holder relatched into a solid link;

FIG. 4 is a view, taken along line 4-4 of FIG. 1, showing the arrangement of the adjustable spring lock;

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FIGS. 5a and 5b are detailed end and plan views, respectively, of the adjustable spring lock;

FIG. 6 is a side view of a multipole circuit breaker, partially in section, with the contacts closed, the cutaway section revealing the location of the main parts within the breaker;

FIG. 7 is a view similar to FIG. 6 with the contacts open;

FIGS. 8a and 8b are enlarged end and side views, respectively, of the hexagonal rod connecting the handles in the multipole breaker;

FIGS. 9a and 9b are enlarged end and side views, respectively, of the trip bar;

FIG. 10 is an isometric view of a three pole breaker having a single handle; and

FIG. 11 is an isometric view of a two pole breaker with a single handle.

Referring to the drawings, the circuit breaker mechanism is contained in a plastic case 1. The case is provided with cavities 2, into which threaded metal inserts are fitted. The inserts are locked in a non-rotating position by the six sided flange on their lower end which engages with a similar cavity portion 3, when two case halves are assembled together. The case halves are secured by rivets passing through holes 4. Expanding gases created during arcing are allowed to escape from inside the case cavity through opening 50.

In FIGURE 1 the contacts 45 and 46 are shown closed so that the electrical circuit consists of terminal 10, coil winding lead 9, coil winding 5, coil winding lead 48, contact bar 37, movable contact 45, stationary contact 46 and terminal 47. When an overload occurs in the electrical circuit, the magnetic flux produced by coil winding 5 is sufiicient to bottom the steel core, in a conventional hydraulic dash pot delay tube 6, against pole piece 11. This produces an increase of flux sufliciently strong to draw the balanced armature 12 up to pole piece 11, against the restraining action of spring 16 mounted on pin 13. The movable end 14 of spring 16 rests against the body of the armature 12 while the fixed end of the spring 15 is anchored against the tab 53 of the adjustable spring lock 52. The adjustable spring lock 52 (shown in FIG. 4) is mounted on pin 13 and has a tab 53 which holds the fixed end 15 of spring 16. The adjustable spring lock 52 is formed of a hexagonal washer and is of such a dimension that one of the six fiat sides engages with the underside of the frame 8 which prevents the washer from rotating. Normally, the lateral thrust of the spring 16 holds the adjustable spring lock 52 at one end of the pin 13 against frame tab 55. To adjust the tension in spring 16, the adjustable spring lock 52 can be moved against the thrust of spring 16 to a point between the ends of pin 13 where the hexagonal washer is free to rotate about pin 13 and extend through a slot 54 provided in frame 8.

When the adjustable spring lock 52 is released, it again assumes a position at the end of pin 13 Where it is held against frame tab '55 and frame 8 so that it cannot rotate.

InFIGURE 1 link 35 and holder 34 are locked together by means of sear pin 20 and cam 24 to form a rigid member in the lever system between pin 29 and 36. When armature 12 is drawn up to pole piece 11, armature leg 17 strikes tab 18 on striker bar 19, thereby rotating sear pin 20 counter-clockwise until the milled slot 21 on the sear pin 20 allows the cam shoe 22 to rotate counter-clockwise about pin 27. As the cam rotates counter-clockwise, pin 26 attached to link 35 is no longer restrained by slot in the cam and the linkage collapses allowing spring 39 to rotate'contact bar 37 counterclockwise about pin 43, thereby separating movable contact 45 from stationary contact 46, as shown in FIG. 2.

Handle spring 31, located on boss 51, has its fixed end resting against the body of the case 1 while movable end 33 is free to rotate the handle 32 counter-clockwise by pressing against pin 29, which extends through the holes in the projection 56 on handle 32. As handle 32 rotates to the position shown in FIG. 3, the force of the contact bar 37 against link 35, exerted by spring 39, forces the cam 24 to rotate clockwise back into a latched position, through pin 26.

Two additional features may be added to a multipole breaker unit, namely, the trip bar 57, shown in FIG. 9, and the hexagonal rod 59, shown in FIG. 8.

When a multipole breaker unit is in the closed contact position, as shown in FIG. 6, the trip bar 57 is held down against the contact bar 37 by the clockwise force of spring 61. When one breaker pole is tripped electrically or the unit is opened by means of the handle 32, tab 60 on link contacts tab 58 on trip bar causing the trip bar 57 and tab 58 to rotate counter-clockwise until the latter strikes the armatures 12 causing the armatures to rotate counterclockwise to the tripped position. Thus, all poles in a multipole unit are tripped by a single electrically tripped pole.

By mounting a hexagonal non-rotating rod 59 through the handles, a choice of one or more handles may be made in assembling the multipole breaker. If a handle is not desired at a particular pole, a link having a hexagonal hole to receive rod 59 is substituted for the handle. The various arrangements of handles on a three pole breaker unit is shown in FIG. 10, while a two pole unit is shown in FIG. 11.

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore to be embraced therein.

I claim:

1. A circuit breaker comprising a housing having a recess therein, first and second terminals extending through said housing, stationary contact means mounted on said first terminal, frame means mounted in said housing, lever means pivotally mounted on said frame means, movable contact means mounted on said lever means and movable into and out of contact with said stationary contact means, current responsive means mounted on said frame means and electrically connected to said second terminal and said movable contact, collapsible toggle means mounted on said frame and operatively connected to move said lever means, handle means on said current responsive means being operatively connected to actuate said toggle means, said toggle means comprising a link pivotally connected on one end to said lever, holder means pivotally connected between the other end of said link and said handle, latch means comprising sear pin means and cam means operatively mounted to lock said link and holder means together, and means drivingly coupling said lever and cam means upon collapse of said toggle mechanism whereby'said lever acts to positively relatch said latch means.

2. In a'multipole circuit breaker unit each pole of which comprises a housing having a recess therein, first and second terminals extending through said housing, stationary contact means mounted on -said first terminal, frame means'mounted in said housing, lever means pivotally mounted onsaid frame, movable contact means mounted on said lever means and movable into and out of contact with said stationary contact, current responsive means mounted on said frame and electrically connected to-said second terminal and said movable contact, collapsible toggle means mounted on said frame and operatively connected to move said lever means, handle means and said current responsive means being operatively connected to actuate said toggle means, said toggle means comprising a link pivotally connected on one end to said lever, holder means pivotally connected between the other end of said link and said handle, latch means comprising sear pin means and cam means operatively mounted to lock said link and holder means together as a rigid member, and means drivingly coupling said lever and cam means upon collapse of said toggle mechanism whereby said lever acts to positively relatch said latch means, trip means interconnecting each said pole of said unit, said trip means comprising a bar having a plurality of tabs equal to the number of poles rigidly mounted thereon, said bar extending through said housing with said tabs being positioned to actuate the toggle mechanism of all said poles upon tripping of one of said poles.

3. A circuit breaker comprising a housing having a recess therein, first and second terminals extending through said housing, stationary contact means mounted on said first terminal, frame means mounted in said housing, lever means pivotally mounted on said frame means, movable contact means mounted on said lever means and movable into and out of contact with said stationary contact means, current responsive means mounted on said frame means and electrically connected to said second terminal and said movable contact, collapsible toggle means mounted on said frame and operatively connected to move said lever means, handle means on said current responsive means being operatively connected to actuate said toggle means, said toggle means comprising a link pivotally connected on one end to said lever, holder means pivotally connected between the other end of said link and said handle, latch means comprising sear pin means and cam means operatively mounted to lock said link and bolder means together, means drivingly coupling said lever and cam means upon collapse of said toggle mechanism whereby said lever acts to positively relatch said latch means, said current responsive means comprising an electromagnet having a coil and an armature, one end of said coil being connected to said second treminal and the other end being connected to said movable contact, a pin mounted on said frame and having said armature mounted thereon, one end of said armature being positioned to be attracted by magnetic flux developed by said coil, the other end of said armature being positioned to rotate said sear pin to electrically trip said toggle mechanism, spring means biasing said one end of said armature away from said coil, said spring means comprising a spring member mounted on said pin with one end engaging said armature, and adjustable spring lock means mounted on said pin and engaging the other end of said spring, said lock means normally bearing against said frame means so as to be non-rotatable, said lock means being selectively displaced to a position where it can be rotated to thereby adjust the tension on said spring. member.

4. A circuit breaker according to claim 1 in which said link is connected to said holder at a point spaced from the end of the former, pin means mounted on said other end of said link, said pin means engaging with said cam means, spring means biasing said lever towards the contact open position, said link and pin transmitting the force of said lever biasing spring means to said cam causing the latter to move to a latched position when said contacts open.

5; .A multipolecircuit breaker unit according to claim 2 further comprising rod means extending through said housings and having said handle means fixedly mounted thereon'whereby the actuation of a single handle means will cause said units to be actuated.

6. A multipole circuit breaker unit according to claim 2 inwhich only one pole is provided with handle means,

said handle means and said linkage means fixedly mountedthereon whereby the actuation of said handle means will cause all of said units to be actuated.

References Cited UNITED STATES PATENTS 2,889,428 6/1959 Kingdon 33743 2,958,751 11/1960 Camp 33521 2,996,589 8/1961 Myers 33743 Cole 335-9 Sprague 335-9 Schwartz 33522 Koval 33522 Harper 335-174 BERNARD A. GILHEANY, Primary Examiner H. BROOME, Assistant Examiner US. Cl. X.R. 

